package FloodFill;

import java.util.LinkedList;
import java.util.Queue;

public class MaxAreaOfIsland {
    int[] dx = new int[]{0, 0, 1, -1};
    int[] dy = new int[]{1, -1, 0, 0};
    boolean[][] vis = new boolean[51][51];

    int m, n;

    public int code(int[][] grid) {
        m = grid.length;
        n = grid[0].length;
        int maxArea = 0;

        for (int i = 0; i < m; i++){
            for (int j = 0; j < n; j++){
                if (grid[i][j] == 1 && vis[i][j] != true){
                    maxArea = Math.max(bfs(grid, i, j), maxArea);
                }

            }
        }

        return maxArea;
    }

    public int bfs(int[][] grid, int i, int j){
        int area = 0;

        Queue<int[]> q = new LinkedList<>();
        q.add(new int[]{i, j});
        vis[i][j] = true;
        area++;

        while (!q.isEmpty()){
            int[] t = q.poll();

            for (int k = 0; k < 4; k++){
                int x = t[0] + dx[k], y = t[1] + dy[k];

                if (x >= 0 && x < m && y >= 0 && y < n && vis[x][y] == false && grid[x][y] == 1){
                    area++;
                    q.add(new int[]{x, y});
                    vis[x][y] = true;
                }
            }
        }

        return area;
    }
}
